1. Field of the Invention
The present invention relates to a panel display, and particularly to a back light module in a liquid crystal display.
2. Description of Related Art
The liquid crystal display as an output of information has been a mature technique applied by the manufactures and in order to comply with various applications, the liquid crystal display can be made big size for being used in the field of liquid crystal television or small size for being used in the field of mobile phone or PDA.
It is necessary for the liquid crystal display to prepare a light source and the back light module is provided as the light source part. The back light module is equipped with light tube set as the light source in case of large size back light module. The light tube set has a plurality of light tubes being aligned with each other vertically in a horizontal direction so that an identical distance between each light tube and the reflection plate can be obtained. The purpose of this arrangement is that the optical distribution (the brilliance distribution) is more uniform while the produced light source projects to the panel.
However, heat is generated during the light tubes emitting light and the back light module is closed to prevent dirty points from entering the back light module. Therefore, how to avoid overheat in the display module is worth us to care.
A conventional heat dissipation as disclosed in the Japanese Patent publication No. 2001-297623, entitled BACK LIGHT MODULE, provides convection holes and fan with a dust free net. But, the prior art is costly in setting up expense thereof and is noisy resulting from the fan. Hence, the prior art is not a perfect design.
Further, the Japanese Patent publication NO. 2001-216807, entitled DIRECT DOWN TYPE BACK LIGHT MODULE, discloses the metal casing of the electrodes attached to the light tubes is treated with corrugation to increase the heat dissipation area so as to bring the generated heat away. However, this type of heat dissipation removes part of the heat generated by the electrodes of light tubes.